When injection molding systems use multi-cavity molds it is frequently desirable to shut-off one or more of the cavities if they are damaged. For example, an eight cavity mold may still be economically used if two of the eight cavities are shut-off.
Runner switches such as those described in U.S. Pat. No. 4,909,725 are currently available. However, these switches require assembly and are expensive to install in the mold plates since they extend entirely through the plate and must be keyed, counter bored and healed from the back of the plate. Also, installation of these switches can result in mismatching of the material supply runners with the slots cut in the switch.
Those concerned with these and other problems recognize the need for an improved runner shut-off for an injection molding system.